Liquid behaves here the same as Lightning, the smart contract in both is created and guaranteed by code on the blockchain. In both cases its multisig UTXO. Pegout and close channel are similar operations, but LN allows a state update. There are no channels or timeouts in Liquid, its just L-BTC UTXOs. Individual LN transactions are not recorded for all eternity (just open/close/anchor). On liquid, they exist in an obscured form that does not reveal values, just the transaction graph.